I have not heard from kaworu, but it seems that the serial number is indeed stored on the internal SD card. If you make an image of the card and then open that image with a binary editor (I used "bvi" on Linux) you can see and change the serial number.

Here I changed my serial number to all zeros:

So the question is what should I change the serial number in my image to be before I start giving out a download link?

I suspect that the recoveryfs partition is just copied on the rootfs partition when applying a factory reset.

If KevinShort only modified the first occurrence of the SN (the one in the rootfs partition), then PeterT may now own a Kobo with the SN from KevinShort's.

In order to clarify this and tell if PeterT's assertion that "the serial #'s are NOT loaded from the recovery partition", could KevinShort tell us wether he modified both occurrences of the SN in the file, and freekobo tell us wether he did check that the SN was actually the one printed on his Kobo's box ?

you did a factory reset and recovered your original SN (the one that is printed on the original label on the kobo packaging)

you did a factory reset and recovered some SN that did not only consist of 0s (and you did not check that it was actually your original SN)

...
...freekobo tell us wether he did check that the SN was actually the one printed on his Kobo's box ?

Thanks !

Yes I checked, its my SN...and the part after the first occurrence (the manufacturer date i think?) is different.

Well, what I did was put KevinShort's image to a spare sd card.
I made an image of the second partition (recovery_fs) and then I applied the image over my broken second partition. I tried a recovery..it worked...and then it updated, I checked the SN again, its the same as it was when I got it.
I made a image of my sd..my SN has 4 occurrences...but on KevinShort's image I located the first one all 0's, the second one I found searching for 'deviceSerial' and located his SN, and then searched his image using his SN...it came up with 12 occurrences. BUT I searched his SN in my image, and was unable to find any occurrences. KevinShort's Image also has text from a book in it...which I found odd....
I have no idea what to make of all this, but ya...thats what I did & found.

Update: I also checked backup image from before I imaged over KevinShort's recovery and my SN appears 15 times in the image... weird... I also checked the image of the recovery partition I made, no SN at all that I could locate using a binary hex editor....

Yes I checked, its my SN...and the part after the first occurrence (the manufacturer date i think?) is different.

Well, what I did was put KevinShort's image to a spare sd card.
I made an image of the second partition (recovery_fs) and then I applied the image over my broken second partition. I tried a recovery..it worked...and then it updated, I checked the SN again, its the same as it was when I got it.

So to keep a backup, we would only need an image of the second partition?

Well, what I did was put KevinShort's image to a spare sd card.
I made an image of the second partition (recovery_fs) and then I applied the image over my broken second partition. I tried a recovery..it worked...and then it updated, I checked the SN again, its the same as it was when I got it.

So PeterT is right, "the serial #'s are NOT loaded from the recovery partition".

But, your experiment does not proove that SN is not read from the microSD card.

Have you tried to run your kobo using the spare sd card made from KevinShort's image ? I wonder what the serial number would be.

Quote:

Originally Posted by freekobo

I made a image of my sd..my SN has 4 occurrences...but on KevinShort's image I located the first one all 0's, the second one I found searching for 'deviceSerial' and located his SN, and then searched his image using his SN...it came up with 12 occurrences.
BUT I searched his SN in my image, and was unable to find any occurrences. KevinShort's Image also has text from a book in it...which I found odd....
I have no idea what to make of all this, but ya...thats what I did & found.

I tried to find the SN of my device in the image I made from the microSD card. I found 15 occurrences (in my previous post, I had found 2 occurrences starting with SN-###, where ### are the first 3 digits of my kobo's SN, this time I only looked for the actual number, without "SN-").
These occurrences are located at the following offsets (in hex this time):
-- 203
-- 211D0063
-- 211F3000
-- 2120C000
-- 23BB5000
-- 29DE8000
-- 31FD1000
-- 338B3000
-- 39D8D000
-- 421E0000
-- 421EA000
-- 421F8000
-- 4220C000
-- 42232000
-- 42BB1A03

I do not know anything about partitions tables and so on, but if the first and second partition sizes are both 256 MB, I expect the first 256 MB of the image file to belong to the first partition (rootfs) and the next 256 MB to belong to the second partition. In this case, everithing before the offset 1000000h would be expected to belong to rootfs, everything between 1000000h and 2000000h would belong to recoveryfs and everything after 2000000h would belong to KOBOeRedear fat32 partition.

Actually, there is no occurrence of the SN anywhere between 1000000h and 2000000h.

Moreover, I suspect the first partition not to start at offset 0.

I would then guess that :

The first occurrence of the serial number is the "original" serial number that is actually read by the device's OS to get the serial number.

Other occurrences of the SN are located somewhere in files stored on the KOBOeRedear fat32 partition (some system files, but also some book-related database)

I am not surprised that the KOBOeReader fat32 partition retains footprints of files related to books that may sometime have been stored there : as far as I remember deleting a file on a fat32 partition only removes informations about this file in the file allocation table but does not really delete the file (this is the principle that is used for recovering deleted files).

I would be curious to see what would be the SN of a device for which a factory reset would be made from an SD card where the first occurrence of the SN (the one that is located at 200h in the image file) would not be removed (or would be faked).